An Experimental Study of Grid Tied Inverter for Renewable Energy Systems

Nowadays, electrical energy produced from the renewable energy sources (RES) tends to increase day by day to meet the increasing energy demand. Also, RES enable energy to be obtained more economically and cleanly. Electrical energy based on the RES is preferred to transfer to electrical grid instead of storing. However, this energy is not transferred to the grid directly because of usability and efficiency. Therefore, grid tied inverter which is transferred electrical energy to the grid is used and inverter control mechanism is so important. On the other hand, the inverter output voltages must be synchronized with grid voltages. So, the phase angle and amplitude of the grid voltages must be obtained accurately and fast. To achieve a suitable grid synchronization, phase locked loops (PLL) are widely used. In this paper, a three-phase space vector pulse width modulation (SVPWM) controlled grid tied inverter is simulated in MATLAB/Simulink and implemented with TMS320F28335 DSP. All simulation and experimental results confirm that the output voltages of the grid tied voltage source inverter are compatible with the grid and grid synchronization is successfully achieved thanks to the PLL algorithm.